Elisa and Western blot

Both these techniques are based on immunology principle but, they have different procedures and applications. So we will see them as similarities and differences.

ELISA vs Western Blot similarities.

Since they follow same principle there are few similarities in between them

SL.NO

ELISA

Western Blot

Principle

Based on Immunological assay

Immunological assay

Method of assay

Reaction between an antigen and antibody forming a complex

Antigen antibody reactions to form a complex

Type of sample

Biological samples

Biological samples only.

Compounds than can be analyzed

Proteins, enzymes, hormones, steroids

Enzymes, proteins, hormones.

Credit: Bio-rad

But they are many differences between these two techniques. These differences help the researcher decide which of the one of the two to take up.

ELISA vs Western Blot Differences.

SL.No

ELISA

Western Blotting

Detects

Antibody or antigen in the tissue

Mostly the antigen in the tissue

Time for experiment

Very fast like in couple of minutes

Very time taking like 2 to 3 days.

Number of samples per experiment

Many sample can be analyzed in a single run like 96 samples per turn using plate readers

Only limited samples like 7 samples per experiment is feasible.

Cost of experiment

Comparatively less expensive.

Very expensive as it requires many basic chemical, gels and even blotting paper.

Accuracy of detection

The sample detection is very accurate and even the quantity can be clearly known.

Though accurate, quantity can not be clearly known.

Technique for operation

It is very easy and even a new experimenter can do with little guidance.

Very complicated and requires practice and standardization of whole procedure.

Sensitivity is enhanced by

Washing and removal of unbound proteins.

Here other interfering proteins are removed by gel electrophoresis.

Types of experiments

ELISA is of different types like direct, indirect, sandwich type.

It is of different types like southern blot, western and even northern blot.

Pictorial demonstration

ELISA is just based on readings by electronic instruments. So it gives only result but no picture

This is based on physical appearance so enables to take photos and depict the result in presentations and publications.

Application

Mostly in health care for diagnosis and also in research.

Mostly in research but less preferred in health care due to time span.

Age of the technique

It is newer technique

Older technique

It appears that those who need a pictorial demonstration for publications and presentations for western blot technique. While, those who need just an accurate result like in health care go for ELISA.

In health care ELISA method is used to identify many diseases like AIDS, Hepatitis and other infections by just taking serum sample. It is also widely used in research as it is less time consuming and easy to perform.

On other hand, Western blotting test may be used as a confirmatory test for HIV after ELISA to avoid any false positives.